• Biodiversity can be measured at many scales
  • maintaining high biodiversity has huge benefits

• Conservation biology focuses on the population level
  • small populations have genetic problems

• Global Change is occurring at unprecedented rates
  • Yes, change has occurred over Earth’s history
  • No, it has never occurred this quickly

• Are we in a new mass extinction?

• Level 1: Genetic Diversity
  • within and among populations
  • loss reduces adaptive potential

• Level 2: Species Diversity
  • number of species in a system
  • local or whole extinctions possible

• Level 3: Ecosystem Diversity
  • variety of ecosystems on Earth
  • provide services to living things

• Genetic Diversity: alleles in populations
  • what happens when a population disappears?

• Species Diversity
  • how many species?
  • how even are the species?
  • roles of dominant, keystone & rare species

• Ecosystem Diversity
  • what services does an ecosystem provide?
  • are the abiotic variables changing?

• Moral code: Each species belongs
  • what happens when a species becomes locally extinct?

• Practical benefits for all 3 biodiversity types
  • genetic diversity a tool for medicines
  • diversity feeds, clothes and houses humans

• Ecosystem Services to humans
  • raw goods
  • health and well being
  • regulation of air, water, etc

• Human activities threaten biodiversity
  • at each scale

• Threats posed by humans fall into 4 categories

1. habitat loss
2. species introductions
3. over-harvesting
4. global change

• Landscape change by humans is largest threat
  • nearly all land surface has been altered
  • causes fragmentation or loss of habitat

• Small populations are the most vulnerable
  • population getting pushed to extinction

• Small populations vulnerable to inbreeding
  • genetic issues of non-random mating

• Small populations vulnerable to genetic drift
  • chance loss of alleles

• Goal: Maintain genetic diversity

• Detect downward trends in population sizes
  • may be a large population

• Prioritize the factors causing decline
  • habitat loss or climate change

• What are the environmental needs of the species?
  • What causes the decline
  • How do we stop it?

• Global warming:

• Climate change:
  • more than just temperature
  • mostly related to post 1950’s

• Global change:
  • e.g. nutrient cycles, biodiversity, land use, sea level rise, ice loss

• Climate change is strongly related to the chemistry of the atmosphere
  • greenhouse gas effect
  • CO₂, CH₄, NO_x & H₂O

• Greenhouse gases intercept and absorb radiation
  • more greenhouse gases = higher temperatures

• Burning of fossil fuels has increased atmospheric CO₂
  • makes biosphere warmer
  • impacts weather and climate

• Humans move nutrients around too much
  • mostly to support agriculture
  • disrupts natural cycling

• Ecosystems may reach critical load of a nutrient
  • nutrient cannot be taken up by plants
  • excess N on crops, leaches to aquatic systems
  • excess N impacts area not intended

• We cannot save all habitats
  • which patches are most crucial?

• Sustainable development
  • better engineer man-made ecosystems
  • food security while reducing nutrient/chemical impacts
  • food security while maintaining ecosystem services

• Curb global emissions
  • can we do it?
  • technology?